If this is first and foremost a TornadoFX applicat...

# tornadofx

[edvin]

If this is first and foremost a TornadoFX application however, I would go about this another way: Create a standard Kotlin class and use as the app class, but call into a Java class where the other guy can put his initialization logic. You can call that method by overriding init() in the App class.